Heat exchange apparatus



` R. MAUTscH 1,920,313

HEAT EXCHANGE APPRATUS Filed Nov. 25, 1931` Patented Aug. 1, 1933 UNITED STATES PATENT OFFICE HEAT EXCHANGE APPARATUS Belgium Application November 25, 1931, Serial No. 577,328, and in Belgium November 28, 1930 7 Claims. (Cl. 257-249.)

The present invention is relative to heat exr change apparatuses such as radiators, evaporators or the like, whose members are constituted by parallel tubes whereon corrugated or puckered ns are threaded. Its object is to provide an improved thermic contact between the ns and the tubes and to strengthen the units assembled of these partis.

For this purpose, instead of making the tubes and the corrugations of the ns of such proportions that only one corrugation of each n is bisected by the tube passing therethrough, according to this invention ns having closeset corrugations are threaded upon relatively thick tubes so that each of the latter passes through several adjacent corrugations of one same n. An increased area of contact is thereby ob, tained between the n and the tube, said increased area causing the iin to grip the tube more firmly, 20 when the latter is expanded in order to secure the ns thereto, for example. Furthermore, the numerous corrugations at the edge of the hole made in the nn, to allow the passage of the tube therethrough, provide said edge with a greater strength in the direction of said corrugations than is the case if the hole is made in a Wider single corrugation, and when the tube is expanded said corrugations so resist distortion of the hole as to cause them to grip the tube tightly, whereby the closest possible contact is secured between the parts.

This invention may be carried into effect in various manners. The fins may be provided with extremely small and close-set puckers,*or'with .larger corrugations su'iciently close-set nevertheless to ensure that each tube shall pass through more than one of them, or groups of small puckers may be caused to alternate with groups of larger corrugations, or again the fin may be so provided with both small and large corrugations that some or all of the latter are themselves puckered and that a tube passing through one large corrugaton only, for example, nevertheless bisects several of the ,small puckers of then.

Variations may be made likewise in the arrangement of the corrugated fins relatively to each other. I2in every case, the fins are arranged in substantially parallel vertical planes,.but.they either may be so-placed as to be spaced from each other or to touch each other, the latter arrangement being preferable since, in that case. no special members are required to keep the nsproperly spaced apart before securing them to the tubes. Furthermore, the apices of the corrugations of two adjacent fins may be arranged torace each other if desired, or the apices oi one fui may be caused to face the depressions in thevfollowing iin. Likewise, the fins threaded upon the tubes either may all be alike, or ns having small puckers may be caused to alternate, in regular sequence or otherwise, with those having large corrugations.

Some constructional embodiments of this invention are illustrateddiagrammatically, by way of example, in the attached drawing, wherein:

Figs. 1, 2 and 3 are plan views of members of a heat exchange apparatus unit, whereof the corrugated or puckered ns are not in contact.

Fig. 4 is a front elevation of one iin, whereof the left hand half is threaded upon a round tube and the right hand half is threaded upon a at- .f

tened tube,

Figs. 5 to 9 are plan views of members, whereof the iins are in contact, and

Fig. 10 is a plan view likewise, of a member the large corrugatlons of whose fins are puckered.

In all the figures of the drawing, a denotes the tubes upon which are threaded ns b the corrugations c of which are sufficiently close-set to ensure that each tube a shall pass through several said corrugations of each n. The corrugations c of Fig. 1 have acute angles, whilst those shown in Fig. 2 are rounded and those illustrated in Fig. 3 are of polygonal cross-section. In these three examples the fins b are not in contact with each other, and the apices of the corruga tions of one n face the depressions in the corrugations of the following iin, but it is manifest that said ns might be applied against each other and their corrugations be arranged apex to apex to form a kind of honeycomb, as shown in Fig. 5. In this figure the corrugations d of the fins are deeper than in the preceding gures, but are nevertheless still suiiiciently close-set to ensure that each tube shall pass through several of them in each iin.

Fig. 6 illustrates a preferred embodiment where-n in fins b, provided with groups of puckers c alternating with corrugationsd, are so arranged that the puckers c are situated at the points of the iin which are pierced by tubes a, whilst corrugations d are in the middle portion of the n between the tubes, and in the outside portions thereof on either side of the tubes. The ns are thus u only in contact with each other at the apices of their major corrugations d, this arrangement having over that of Fig. 5 the advantage that the fluid flowing between said ns is enabled to sweep round the whole periphery of the tubes and over the entire area of the puckers c whereas, in the arrangement illustrated in Fig. -5, it cannot flow in the cells or honeycomb situated immediately below or above the tubes and obstructed by the same, and incomplete use is therefore made of a considerable portion of the heating surface.

In Fig. 7 puckered fins c are shown to alternate with corrugated ns d, partitioned cells thus being formed.

The relatively large corrugations d of the iins illustrated in Fig. 8 are themselves provided with puckers c, thisl result being secured, for example, by rstly puckering the iin and corrugating or folding it again thereafter into larger waves d. Though comparatively large, the latter are nevertheless sufficiently cose-set to allow tube a to pass through several of them in each n.

An arrangement analogous to that of Fig. 8 is illustrated in Fig. 9, with this difference however 'that only the large corrugations d, r portions of such corrugations touching tube a, are providedwith puckers c, whereas the surface of the remaining corrugations d of the iin isl smooth.

The single 1in illustrated in Fig. 10 is provided with corrugations e whose slopes are themselves puckered, as in the two foregoing examples, but in this form of construction said corrugations e are so proportioned that only one of them is traversed by each tube a. Thanks to the presence of the small puckers c, several of which are bisected by tube a passing through corrugation e of which they are integral the object of the invention is nevertheless fulfilled, since said small puckers increase the area of contact between the fin and the tube.

All the forms of iins hereinbefore described may of course be spaced apart or be arranged in contact with each other individually or in groups, the invention extending to every possible disposition permitting each tube to pass through several large or small corrugations of each 1in.

From Fig. 4 will be seen the resistance which the edges of the holes f in the ns oppose to distortion when the tubes a are expanded, and especially to distortion longitudinal of puckers c, said resistance being due to the presence at the upper and lower edge of` each hole of a suilcient number of said puckers to endow said edges with a high resistance to crushing stresses. Said resistance is further enhanced by forming the fin with a double corrugation, as shown in Figs. 8, and 9 and 10. Tube a has been shown in Fig. 4 by way of example on1y,and might be varied by being made slightly ovoidal, for example, in order to promote the ow of the streams of uid at either side of the tubes.

Preferably, the Iins are formed of aluminium or the like light metals or alloys but the invention is not, of course, limited to the use of any particular metal, nor to the constructional details hereinbefore described and illustrated by way of example.

I claim:

1. In a heat exchange apparatus, parallel tubular members, fins threaded on said tubular members, said ns having corrugations formed therein, said corrugations comprising groups of large corrugations and groups of small corrugations both extending parallel with the direction of ilow of the medium surrounding said tubes, said tubular members being expanded internally, said ns gripping the periphery of each of said members along a sinuous line and forming therewith a rigid whole.

2. In a heat exchange apparatus, parallel tubular members, ns threaded on said tubular members, said ns having corrugations and puckers of rounded outline formedtherein, said corrugations and said puckers extending parallel with the direction of flow of the medium surrounding said tubes.

3. In a heat exchange apparatus, parallel tubular members, ns threaded on said tubular members, said ns having formed therein groups of corrugations and groups of puckers in alternating relation, said groups of corrugations being located between adjacent tubular members, said groups of puckers being intersected by said members.

4. In a honeycomb heat exchange apparatus, ns having corrugations formed therein, and parallel tubular members passing through a plurality of said iins, said tins being set substantially at right angles to said tubular members and contacting with each other at the apices of said corrugations to form the cells of said honeycomb between said tubes, said corrugations being spaced apart from each other around said tubes.

5. In a heat exchange apparatus, parallel tubular members, fins having small puckers formed therein, and other fins having corrugations formed therein, said fins being threaded upon said tubular members and said corrugated ns alternating with said puckered fins.

6. In a honeycomb heat exchange apparatus,

,tubular members, and substantially parallel fins threaded upon said tubular members, said ns having formed therein corrugated portions and puckered portions, said corrugated portions being located between said tubular members and contacting at the apices of their corrugations to form the cells of said honeycomb, said puckered portions being located around the points where said tubular members pass through said fins, and said tubular members bisecting a plurality of said puckers in said puckered portions of said fins.

7. In a honeycomb heat exchange apparatus, fins having substantially parallel corrugations formed therein, some of said corrugations being plain and other of said corrugations being puckered, and tubular members passing through said iins, said puckered corrugations being located around the points Where said tubular members pass through said ns and said puckered corrugations contacting at their apices to form the cells of said honeycomb.

and said plain corrugations ROBERT MAUTSCH. 

